Techniques for generating an optimal running locus of a vehicle and performing various driving assistances and automatic driving by utilizing the running locus have been developed. The apparatus described in Patent Literature 1 detects a road shape in front of an own vehicle, computes an own vehicle future position according to the road shape and the running speed of the own vehicle, and displays the own vehicle future position by projecting it onto a windshield. In the case of a curved road in particular, a clipping point which is a characteristic point of the curved road and the own vehicle future position are displayed together as being projected onto the windshield. On the other hand, Non Patent Literature 1 discloses a method of generating an optimal running locus for running through a curved road at the fastest speed.    Patent Literature 1: Japanese Patent Application Laid-Open No. 2005-228139    Non Patent Literature 1: FUJIOKA Takehiko and EMORI Daisuke, “Numerical Analysis of Minimum-Time Cornering”, Transactions of Society of Automotive Engineers of Japan, Vol. 24, No. 3, July 1993, p 106-111.